Fireproof metal ceiling



Jan.14,`1941; J. H. YOUNG mL 2,228,650

FIR-EPROOF METAL CEILING Filed May 15, 193e y INVENTORS Bydfwg Patented Jan. 14, 1941 PATENT OFFICE f i 2,228,650 Fmlirnoor METAL oEmrNG James Howard Young and Paul W. Jenkins, Pittsburgh, Pa., assignors to H. H. Robertson Company, Pittsburgh, Pal., a corporation of v Pennsylvania Application May 13,

4 claims.'

This invention relates to a fireproof ceiling construction.

The object of the invention is to provide a novel .ceiling structure which may be erected in a simple economical manner and which provides `efficient reproong for the load bearing floor members from which the ceiling is preferably suspended.

` With thisv general object in view, and such others as may hereinafter appear, the invention consists in the ceiling structure hereinafter described and particularly dened-in the claims at the end of this specication.

In the drawing illustrating the preferred embodiment of the invention, Fig. 1 is a. cross-sectional view of the present ceiling structure; Fig. 2 is a perspective view of ,a portion of the oor and ceiling structure shown in Fig. .1, and Fig. 3 illustrates a modiiieddorm of pan used in the present ceiling structure. In general, the present invention contemplates a metal ceiling Vstructurecomprising a series of shallow pans suspendedr from the load bearing members of a floor. The under surfaces of the metal pans cooperate to form in effect a continuous ceiling surface and the individualmetai pans may and preferably `will be provided with suiicient unexpended vermiculite so that when exposed to fire conditions, a sulntantial thickness of expanded vermiculite is produced between the metal pans and the floor members whereby to eiilcientl-y reproof and insulate the same.

The present ceiling structure is particularly suitable for use in fireproong a metal oorof the type now sold under the name of Robertson Keystone Floor and which may be of a structure g' illustrated in the' patent to Young, No. 1,867,433. The improved ceiling structure comprises a series of shallow metal pans I 0 suspended from the load bearing members I2 cfa /oor. 'I'lie oor I2 may, 'as above stated, comprise the cellular metal oor forming the subject matter of the Young patent above referredl to. As herein shown, the side walls of the metal pans I2 may be extended and bent to form hook members I8 by which the metal paris may be suspended upon supporting members I6 welded or otherwise secured to the bottom of the metal cells constituting the load supporting beams or' members of the floor structure. The metal pans Ill are each provided with a suilicient quantity of-unexpanded vermiculite either in a dry form or in the .form of a slab comprising unexpanded vermiculite and a binder such as gypfsum, so that when the ceiling structure is exposed to fire conditions, a body of expanded vermiculite of substantialthickness is produced in the space ists, serial No. 207,722

(ci. iss-'sm between the ceiling formed by the pans I0 and the load supporting members I2 of the floor, thus eiiciently insulating the iloor from the' fire and eiectively ireproonng the same. The shallow 4metal pans I0 are preferably suspended from the oor at a -sucient distance to aord room for the expansion of the vermiculite under iire conditions and the production of the desired thickness of the insulating and ilreproong vermiculite member between the ceiling and theiloor.

' It has been found that the fire resistance period of the ceiling structure above described is limited `by the resistance of the metal of the pans through oxidation under, the fire conditions. Ordinary black steel4 asthe material for the pans has been found to be satisfactory for lre exposures of considerable duration. Chromium Steels and the like which are resistant ,tohigh temperature oxidation may be used to extend the fire-resistive period. Among the various non-inflammable` materials with which` I have experimented, a composite or laminated sheet comprising an asbestos felt layer attached by a metallic coating'as a terne coating to the exposed surface of a steel sheet in accordance with the process set forth in the Coman Patents Nos. 1,862,332 and 2,073,334, has been' found to offer substantial resistance to oxidation and to be particularly economical for use in the production of the present ceiling structure to provide a resistive surface of improved appearance.

The present invention contemplates the combination of ametal pan ceiling construction and unexpanded vermiculite as a ilreproof cover for floor members, and particularly steel floor members. One typepf metal ceiling construction now commercially used comprises a series of perforated metal pans backed by a sound-absorbing element. In accordance with the present invention, the fire-resistive period of this type of acoustical ceiling may'be improved by the use of unexpanded vermiculite in. conjunction with the sound-abit will be understood that the invention may bel s embodied in other forms within the scope ofthe following claims. -Y

pans, and a sufficient quantity of lunexpanded vei'- miculite contained within said pans to produce under ire exposure a relatively thick layer of expanded vermiculite between the metal ceiling and the -oor members, said pans being of a depth greater than the thickness of unexpanded vermiculite contained therein whereby upon expansion the expanded vermiculite 'is retained in operative position by said pans.

2. The combination with a cellular metal floor .and a series of shallow metal pans suspended below and at a distance from the iloor and cooperating to form a substantially continuous ceiling, said metal pans being provided with a sufllcient quantity of unexpanded vermiculite to produce under fire exposure a relatively thick layer of expanded vermiculite between the metal ceiling and the floor whereby to reproof the same, said pans being of a depth greater than the thickness of unexpanded vermiculite contained therein whereby upon expansion the expandedl vermiculite is retained in operative position by said pans.

3. The combination with the load bearing members of a floor, of a series of shallow metal pans suspended therefrom with the bottom of the pens forming a substantially continuous metal ceiling, each metal pan comprising a laminated structure of an underlying asbestos layer secured tofthe metal of the pan by a terne coating, said pans con.

taining sumcient unexpanded vermiculite to permit the production of a relatively thick layer of expanded vermiculiteiunder re conditions, said pans being'of a depth greater than the thickness of unexpanded vermiculite contained therein whereby upon expansion the expanded vermiculite is retained in operative position by said pans.

A 4. The combination with the load bearing members of a iioor, of a series of shallow metal pans suspended therefrom with the bottom of the pans forming a substantially continuous metal ceiling, each metal pan comprising a laminated structure oi! an asbestos layer secured to the metal of the pan by a metallic coating, said pans containing suillcient unexpanded vermiculite to permit the production of a relatively thick layer of expanded vermiculite under fire conditions, said pans being of a depth greater than the thickness of unexpanded vermiculite contained. therein whereby upon expansion the expanded vermiculite is retained in operative position by said pans.

JAMES HOWARD YoNG. PAUL w. JENKINS.l 

